This application relates generally to power generation. More specifically, this application relates to the use of phase transitions to maintain thermal gradients in power generation.
The use of thermodynamic techniques for converting heat energy into mechanical, electrical, or some other type of energy has a long history. The basic principle by which such techniques function is to provide a large temperature differential across a thermodynamic engine and to convert the heat represented by that temperature differential into a different form of energy. Typically, the heat differential is provided by hydrocarbon combustion, although the use of other techniques is known. Using such systems, power is typically generated with an efficiency of about 30%, although some internal-combustion engines have efficiencies as high as 50% by running at very high temperatures.
Conversion of heat into mechanical energy is typically achieved using an engine like a Stirling engine, which implements a Carnot cycle to convert the thermal energy. The mechanical energy may subsequently be converted to electrical energy using any of a variety of known electromechanical systems. Thermoelectric systems may be used to convert heat into electrical energy directly, although thermoelectric systems are more commonly operated in the opposite direction by using electrical energy to generate a temperature differential in heating or cooling applications.
While various power-generation techniques thus exist in the art, there is still a general need for the development of alternative techniques for generating power. This need is driven at least in part by the wide variety of applications that make use of power generation, some of which have significantly different operational considerations than others.